Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of the first image in a sequence of a display screen or portion thereof with transitional graphical user interface, showing our new design in a first embodiment;

FIG. 2 is a front view of the second image thereof;

FIG. 3 is a front view of the third image thereof;

FIG. 4 is a front view of the first image in a sequence of a display screen or portion thereof with transitional graphical user interface, showing our new design in a second embodiment;

FIG. 5 is a front view of the second image thereof; and

FIG. 6 is a front view of the third image thereof.

FIG. 7 is a front view of the first image in a sequence of a display screen or portion thereof with transitional graphical user interface, showing our new design in a third embodiment;

FIG. 8 is a front view of the second image thereof;

FIG. 9 is a front view of the third image thereof;

FIG. 10 is a front view of the first image in a sequence of a display screen or portion thereof with transitional graphical user interface, showing our new design in a fourth embodiment;

FIG. 11 is a front view of the second image thereof;

FIG. 12 is a front view of the third image thereof;

FIG. 13 is a front view of the first image in a sequence of a display screen or portion thereof with transitional graphical user interface, showing our new design in a fifth embodiment;

FIG. 14 is a front view of the second image thereof;

FIG. 15 is a front view of the third image thereof;

FIG. 16 is a front view of the fourth image thereof;

FIG. 17 is a front view of the fifth image thereof;

FIG. 18 is a front view of the first image in a sequence of a display screen or portion thereof with transitional graphical user interface, showing our new design in a sixth embodiment;

FIG. 19 is a front view of the second image thereof;

FIG. 20 is a front view of the third image thereof;

FIG. 21 is a front view of the fourth image thereof; and,

FIG. 22 is a front view of the fifth image thereof.

The broken lines showing the display screen or portion thereof in FIGS. 1-3, 7-9, 13-17 , and an alternate display screen or portion thereof in FIGS. 4-6, 10-12, 18-22 form no part of the claimed design. The remaining broken lines show portions of the transitional graphical user interface that form no part of the claimed design. 

CLAIM The ornamental design for display screen or portion thereof with transitional graphical user interface, as shown and described. 